BRIEF—Uncertainty over $590 million Moderna bird flu contract

US health officials are reportedly reexamining a $590 million agreement awarded to Moderna (Nasdaq: MRNA) for the development of its bird flu vaccine, according to sources cited by Bloomberg. 

Moderna, which has not commented on the reports, saw its stock fall over 5% in after-hours trading. 

The contract, granted in January, was in addition to $176 million previously provided by the US Department of Health and Human Services to support the late-stage development of an mRNA-based H5N1 vaccine.

Moderna recently announced plans to move its experimental bird flu vaccine, mRNA-1018, into late-stage trials after promising early trial results. The company intends to present its findings at an upcoming medical conference.

Meanwhile, the US government has pledged up to $1 billion to combat the spread of bird flu, which has severely impacted poultry and dairy livestock and led to a small number of human infections.